Extract common code to enable/disable, show/hide controls on some condition

Question

I have few controls on my page which I want to show/hide and/or enable/disable on some condition.

Images to help illustrate the requirements:

screenshot1 screenshot2 screenshot3

Following is the code to show/hide, enable/disable the controls. Please review it and tell me how I can extract common code.
Any other suggestion are also more than welcome.

// Change controls status (enable/disable, show/hide) on the basis of selected item
protected void ddlLocationType_SelectedIndexChanged(object sender, EventArgs e)
{
 int locationType = 0;
 int.TryParse(ddlLocationType.SelectedItem.Value, out locationType);
 EnableRelavantLocaitonControls(locationType);
}
private void EnableRelavantLocaitonControls(int locationType)
{
 switch (locationType)
 {
 case 0:
 DefaultControlsPosition();
 break;
 case 1:
 EnableControlsForProvince();
 break;
 case 2:
 EnableControlsForDistrict();
 break;
 case 3:
 EnableControlsForTehsil();
 break;
 case 4:
 EnableControlsForUC();
 break;
 case 6:
 EnableControlsForVillage();
 break;
 default:
 DefaultControlsPosition();
 break;
 }
}
// Show all drop downs.
// Hide all textboxes and disable all controls.
private void DefaultControlsPosition()
{
 ddlProvince.Enabled = false;
 ddlProvince.Visible = true;
 txtProvince.Enabled = false;
 txtProvince.Visible = false;
 ddlDistrict.Enabled = false;
 ddlDistrict.Visible = true;
 ddlDistrict.Enabled = false;
 txtDistrict.Visible = false;
 ddlTehsil.Enabled = false;
 ddlTehsil.Visible = true;
 txtTehsil.Enabled = false;
 txtTehsil.Visible = false;
 ddlUC.Enabled = false;
 ddlUC.Visible = true;
 txtUC.Enabled = false;
 txtUC.Visible = false;
 ddlVillage.Enabled = false;
 ddlVillage.Visible = true;
 txtVillage.Enabled = false;
 txtVillage.Visible = false;
}
// Show all drop downs except province drop down and disable all.
// Show and enable TextBox for province instead of drop down so user can 
// enter name of province.
private void EnableControlsForProvince()
{
 ddlProvince.Enabled = false;
 ddlProvince.Visible = false;
 txtProvince.Enabled = true;
 txtProvince.Visible = true;
 ddlDistrict.Enabled = false;
 ddlDistrict.Visible = true;
 ddlDistrict.Enabled = false;
 txtDistrict.Visible = false;
 ddlTehsil.Enabled = false;
 ddlTehsil.Visible = true;
 txtTehsil.Enabled = false;
 txtTehsil.Visible = false;
 ddlUC.Enabled = false;
 ddlUC.Visible = true;
 txtUC.Enabled = false;
 txtUC.Visible = false;
 ddlVillage.Enabled = false;
 ddlVillage.Visible = true;
 txtVillage.Enabled = false;
 txtVillage.Visible = false;
}
// Show and Enable 'Province' drop down.
// Hide and Disable 'District' drop down.
// Show and Enable 'District' text box.
// Show and Disable all other drop downs beneath District.
private void EnableControlsForDistrict()
{
 ddlProvince.Enabled = true;
 ddlProvince.Visible = true;
 txtProvince.Enabled = false;
 txtProvince.Visible = false;
 ddlDistrict.Enabled = false;
 ddlDistrict.Visible = false;
 txtDistrict.Enabled = true;
 txtDistrict.Visible = true;
 ddlTehsil.Enabled = false;
 ddlTehsil.Visible = true;
 txtTehsil.Enabled = false;
 txtTehsil.Visible = false;
 ddlUC.Enabled = false;
 ddlUC.Visible = true;
 txtUC.Enabled = false;
 txtUC.Visible = false;
 ddlVillage.Enabled = false;
 ddlVillage.Visible = true;
 txtVillage.Enabled = false;
 txtVillage.Visible = false;
}
private void EnableControlsForTehsil()
{
 ddlProvince.Enabled = true;
 ddlProvince.Visible = true;
 txtProvince.Enabled = false;
 txtProvince.Visible = false;
 ddlDistrict.Enabled = true;
 ddlDistrict.Visible = true;
 txtDistrict.Enabled = false;
 txtDistrict.Visible = false;
 ddlTehsil.Enabled = false;
 ddlTehsil.Visible = false;
 txtTehsil.Enabled = true;
 txtTehsil.Visible = true;
 ddlUC.Enabled = false;
 ddlUC.Visible = true;
 txtUC.Enabled = false;
 txtUC.Visible = false;
 ddlVillage.Enabled = false;
 ddlVillage.Visible = true;
 txtVillage.Enabled = false;
 txtVillage.Visible = false;
}
private void EnableControlsForUC()
{
 ddlProvince.Enabled = true;
 ddlProvince.Visible = true;
 txtProvince.Enabled = false;
 txtProvince.Visible = false;
 ddlDistrict.Enabled = true;
 ddlDistrict.Visible = true;
 txtDistrict.Enabled = false;
 txtDistrict.Visible = false;
 ddlTehsil.Enabled = true;
 ddlTehsil.Visible = true;
 txtTehsil.Enabled = false;
 txtTehsil.Visible = false;
 ddlUC.Enabled = false;
 ddlUC.Visible = false;
 txtUC.Enabled = true;
 txtUC.Visible = true;
 ddlVillage.Enabled = false;
 ddlVillage.Visible = true;
 txtVillage.Enabled = false;
 txtVillage.Visible = false;
}
private void EnableControlsForVillage()
{
 ddlProvince.Enabled = true;
 ddlProvince.Visible = true;
 txtProvince.Enabled = false;
 txtProvince.Visible = false;
 ddlDistrict.Enabled = true;
 ddlDistrict.Visible = true;
 txtDistrict.Enabled = false;
 txtDistrict.Visible = false;
 ddlTehsil.Enabled = true;
 ddlTehsil.Visible = true;
 txtTehsil.Enabled = false;
 txtTehsil.Visible = false;
 ddlUC.Enabled = true;
 ddlUC.Visible = true;
 txtUC.Enabled = false;
 txtUC.Visible = false;
 ddlVillage.Enabled = false;
 ddlVillage.Visible = false;
 txtVillage.Enabled = true;
 txtVillage.Visible = true;
}

• Jeff Mercado: You need to put your requirements in words here or a embedded picure... you can't expect us to click through your links just to figure out what you're doing...

Answer 1

First possible refactoring: define an enumeration for the three possible states

enum InputState{
 Hidden,
 Disabled,
 Enabled
}

and use it with an extension method (or by extending the class)

public static void SetVisibility(this Control ctrl, InputState state){
 switch(state){
 case InputState.Hidden:
 ctrl.Enabled = false;
 ctrl.Visible = false;
 break;
 case InputState.Disabled:
 ctrl.Enabled = false;
 ctrl.Visible = true;
 break;
 case InputState.Enabled:
 ctrl.Enabled = true;
 ctrl.Visible = true;
 break;
 }
}

Answer 2

1. Start by creating a list of objects which contain the connection between a location type and the relevant controls. First create a new class to hold this information:

   public enum LocationType
   {
    Undefined = 0,
    Province = 1,
    District = 2,
    ...
   }
   public class LocationControl
   {
    public LocationType Type { get; set; }
    public TextBox TextBox { get; set; }
    public ComboBox ComboBox { get; set; }
   }
   private List<LocationControl> _myControls = new List<LocationControl>();
   

2. Then, create type-control links:

   private void InitControls()
   {
    // a better approach might be to create all controls here,
    // but if you want to use the VS designer, this will do
    // (just call it inside OnLoad or something)
    _myControls.Add(new LocationControl()
    {
    Type = LocationType.Province,
    TextBox = txtProvince,
    ComboBox = ddlProvince
    });
    _myControls.Add(new LocationControl()
    {
    Type = LocationType.District,
    TextBox = txtDistrict,
    ComboBox = ddlDistrict
    });
    ...
   }
   

3. Once you have this information, enabling the right control is trivial:

   private void EnableRelevantLocationControls(LocationType type)
   {
    // enable this input
    var activeLocation = _myControls.Find(c => c.Type == type);
    Enable(activeLocation);
    // disable all other inputs
    var inactiveLocations = _myControls.Where(c => c.Type != type);
    foreach (var location in inactiveLocations)
    Disable(location);
   }